of westminster



F. G. L. JOHNSON. SHELL FUSE.

APPLICATION FILED Nov. II. Isla.

1,313,298. PaIenIedAug.19,1919.

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UNTTED STATES PATENT oEEicE.

FREDERICK GEOEFREY LEES JOHNSON, OF WESTMINSTER, LONDON, ENGLAND,ASSIGNOR TO VICKERS, LIMITED, OF WESTMINSTER, LONDON, ENGLAND.

SHELL-FUSE.

To all whom t may concern.' f

Be it known that I, FREDERICK GEorrREr LEES JOHNSON, a subject of theKing of Great Britain, residing at Vickers House, Broadway, Westminster,in the county of London, England, have invented certain new and usefulImprovements incr Relating to Shell-Fuses, of which the fo-llowing is aspecification.

This invention relates to shell fuses of the time type ignited on firingthe shell from a gun, and has for its chief object to render the fuseindependent'of atmospheric or ballistic conditions.

According to this invention the fuse is so constructed as to bemaintained gas tight throughout tbe combustion of the slowburningcomposition during the flight of the shell, which composition forms aseal until the combustion has advanced sufficiently to break through andignite the shell charge. Owing to the complete internal combustion thefuse is shielded from external influences and its action is therebyrendered more reliable.

According to one construction embodying this invention the fuse bodycarries a plug screwed into one end of the body, the other end of whichis solid, the plug carrying a column of slow-burning composition theouter end of which is supported by a crossing column, which may be ofquick-burning powder, lying in a cross channel at the end of the plug.The slow-burning column is therefore supported against internal pressureand enables a complete gas tight inclosure to be obtained, within whichis a movable pellet provided with small shearing lugs and a percussioncap.

When the shell is fired from the gun the Shock of discharge breaksthesmall shearing lugs on the pellet and cau-ses the latter to strike aprojecting peg in the rear part of the fuse body. The percussion capcarried in the pellet is thereby exploded and the flash passes throughthe center of the pellet and impinges on the inner end of the column ofslow-burning composition. After a certain interval of time, theslow-burning composition is consumed and th-e flame reaches the outerend of the plug and ignites the shell charge through the cross column ofquick-burning powder.

In order that the said invention may be clearly understood and readilycarried into Specification of Letters Patent.

Patented Aug. 19, 1919.

Application led November 11, 1918. Serial No. 262,056.

effect I will now describe the same more fully with referencev to theaccompanying drawing, which shows in longitudinal section a fuseconstructed in accordance with this invention. c

`A'is the fuse body. B is a plug screwed into the inner end of the bodyand carrying the column b of slow-burning composition at the outer endofwhich is the cross column b of the samecomposition, or of a quickburning powder, lying in the cross channel at the end of the plug. C isthe pellet sleeve having the small shearing lugs. c at one end lyingagainst the shoulder a in the fuse body, the pellet being adapted toslide in the chamber a of the body. D is the percussion cap. E is thebase of the shell to which the fuse is fitted. Y

The pellet illustrated comprises the sleeve C, screw threaded internallyto receive the two small plugs c', c2. Between the two plugs is thepercussion cap D which is carried by the plug 0 and bears against anextension of the plug c2, the latter being formed with the axial hole c3for the passage of the flash from the percussion cap to the compositionb. The sleeve C is held from forward movement by the ring c4 interposedbetween the front surface of the Sleeve and the plug B.

The body A of the fuse is provided with the internal peg F which effectsthe iring of the percussion cap when the shell is fired from the gun,the lugs c breaking off and `allowing the plug to fly rearwardly so thatthe cap strikes against the peg F and is fired. The flash from thepercussion cap passes through the passage o3 and the forward end of thespace or chamber a', reaching the rear end of the column Z) and slowlyburning the composition which burns until the cross column b, preferablyof quick burning composition, is ignited when the main charge of theshell is fired.

Owing to the combustion taking place under gas tight conditions, thefuse may be placed in the base, nose or any other convenient part of theshell. It is shown in the base E. The air space a allowed within thefuse body is suiciently large t-o prevent undue pressure from thecombustion of the slow-burning composition. The columns b, b of .thecomposition may be replaced by a time setting device by which theeffective length of the column can be varied, the present invention notbeing restricted to any particular construction of fuse.

What I claim and desire to secure by Letters Patent of the United Statesis l. In a shell fuse, a gas tight fuse body, ring mechanism containedin the s aidbody, and a column of slow burning composition which forms a'seal maintaining the fuse gas tight until the combustion of the saidcomposition is advanced sufficiently to break through and ignite theShellcharge.

2. In a shell fuse, a gas tight fuse body, firing mechanism containedwithin the said body, a plug secured vin the end of the body having anaxial channel and aocommunic-ating cross channel filled with columns ofcombustible which form a seal maintaining the fusel gas tight until thecombustion of the aXial and cross columns has 'advanced sufficiently tobreak through and ignite the shell charge. Y

3. In a shell fuse, a gas tight fuse body, a plug secured in the innerend of the said body and provided with a channel lled with slow burningcomposition forming a seal maintaining the fuse gas tight, a pelletmounted in the fuse body and provided with a flash passage, a percussioncap on the pellet and a projecting member within the body adapted tomeet the percussion cap on the shell being fired from Ithe gun, theflash from the cap passing through the passage in the pellet to ignitethe inner end of the column of the slow burning composition.

4. In `a shell fuse, a gas tightrfuse body, firing mechanism containedwithin the said body, a plug screwed into one end of the body andprovided with an aXial passage and an external communica-ting crosschannel, la column of slow burning composition placed within the axialchannel and a column of quick burning powder in the cross channel, thesaid columns forming a seal maintaining the fuse gas tight untilcombustion of the composition has advanced sufficiently to break throughand ignite the quick burning powder and the shell charge.

FREDERICK GEOFFREY LEES JOHNSON.

Copies o1.' this patent may be obtained :or five cents each, byaddressing the Commissioner of Patents. Washington, D. C.

